Case Study
Has this person used Cocaine in the past 3 months?
FTS model of best practice shows how hair segmentation and expert interpretation of data were vital for the right outcome in court.
Others say he has used Cocaine in the last 3 months, we say he hasn’t.
Obtaining reliable evidence from Drug and Alcohol tests in care proceedings is a complex issue.
Test results should not be taken at face value or they can be very misleading unless:
The following case history demonstrates that drug testing does not always find the right answer to the important question; whether drugs are a factor in the case. They show that when the incorrect test profile is used and an interpretation of the results is made simply on whether drugs are above or below a defined cut-off in the hair sample tested, then frequently the wrong conclusions are made and consequently the court can often be misled.
An alternative laboratory carried out a simple standard test with no additional detailed investigation
A hair sample was collected at the end of May to carry out a test for cocaine to cover a 3-month history. The hair sample was cut to a single section of 3cm in length (un-segmented). No client interview conducted.
Cocaine and one metabolite above cut-off, interpreted as Positive and the laboratory concluded:
“The levels observed in the 0-90 day segment indicate that the donor consumed cocaine on multiple occasions within the time period tested.”
The hair was not segmented providing a “blunt instrument” to assess the pattern of drug use, which provided a misleading conclusion. All parties and the court therefore understandably assumed that the client had been using cocaine during the approximate 3- month period, from March to May. This result was to be the determining factor in the decision-making process with regards to the child’s residence.
Establishing key facts with our detailed client questionnaire
The 25 minute client interview established in summary:
Hair sample cut to 4cm and segmented into 4 x 1cm segments
FTS completed the testing and investigated all factors that could influence the outcome and interpretation of the test results. The profile of very high levels in hair section 4 reducing significantly and progressively in each section to very low levels in hair section 1, combined with a negative urine test, clearly represented carry-over of cocaine in the dormant hair from previous use. FTS used their experience referencing their unique and comprehensive database to produce a report with a clear and unambiguous conclusion on the client’s pattern of drug use, based on the balance of probabilities.
FTS experts reveal a Negative result over the same period and concluded on a balance of probabilities:
“These results are compatible with the client using cocaine on a frequent basis up to around February. Cocaine use appears to have stopped sometime during February or possibly early March and there does not appear to have been any active cocaine use for the subsequent period of approximately 3 months up to the point of sample collection at the end of May. These results appear to be consistent with the clients’ declaration.”
When the appropriate test profile is used and results interpreted in context with key factors (in particular, previous very frequent use) and referenced against our unique database, FTS can provide the most probable and reliable conclusion.
This conclusion is often different from other laboratories, despite both laboratories finding similar average levels in the hair, which highlights the serious implications of using an inappropriate test profile and taking results at face value. The different conclusion in this case would probably lead to a different decision being made with regards to the child’s residence. In certain cases, given the client has honestly declared previous use and has shown motivation to stop using, then these results may provide justification for the cost of additional testing to ensure abstinence from drug use is maintained, which means decisions can be made with more confidence.